1. Field of the Invention
The present invention relates to apparatus for conditioning air or another fluid medium and, more particularly, to such an apparatus employing a heat engine having first and second refrigerant coils, one disposed in thermal exchange relation with the medium to be heated or cooled and the other disposed in thermal exchange relation with a liquid.
2. Prior Art
U.S. Pat. No. 2,689,090 describes a heating system comprising a heat engine having a first refrigerant coil mounted for thermal exchange with an atmosphere to be heated and a second refrigerant coil mounted for thermal exchange with a liquid, the temperature of which is determined by an atmospheric heat absorber connected in series relationship with a liquid-carrying coil disposed within the soil of the earth.